Add better exclusion tags for pre-processor in examples

doc/modules/ROOT/pages/examples.adoc

@@ -33,7 +33,7 @@ Error Detected: Overflow detected in unsigned addition
 ====
 [source, c++]
 ----
-include::example$basic_usage_stacktrace.cpp[]
+include::example$basic_usage_stacktrace.cpp[tags=**;!exclude]
 ----
 
 Output on Linux x64:
@@ -263,7 +263,7 @@ The example approximates the same effect with a type alias so it compiles either
 ====
 [source, c++]
 ----
-include::example$safety_profile.cpp[]
+include::example$safety_profile.cpp[tags=**;!exclude]
 ----
 
 Output without `BOOST_SAFE_NUMBERS_INTEGER_SAFETY_PROFILE` (silent wrap-around):
@@ -342,7 +342,7 @@ IMPORTANT: The header `<boost/safe_numbers/fmt_format.hpp>` is *NOT* part of the
 ====
 [source, c++]
 ----
-include::example$fmt_format.cpp[]
+include::example$fmt_format.cpp[tags=**;!exclude]
 ----
 
 Output:

examples/basic_usage_stacktrace.cpp

@@ -5,6 +5,7 @@
 #include <boost/safe_numbers/unsigned_integers.hpp>     // For safe_numbers types
 #include <boost/safe_numbers/iostream.hpp>              // For safe_numbers <iostream> support
 #include <boost/exception/diagnostic_information.hpp>   // For boost::diagnostic_information
+// tag::exclude[]
 
 #if (defined(__x86_64__) || defined(_M_X64)) && !defined(__MINGW32__) && !defined(__CYGWIN__)
 
@@ -16,10 +17,13 @@
 #pragma GCC diagnostic ignored "-Wold-style-cast"
 #endif
 
+// end::exclude[]
 #include <boost/stacktrace.hpp>                         // For boost::stacktrace::from_current_exception
+// tag::exclude[]
 
 #endif
 
+// end::exclude[]
 #include <iostream>
 #include <cstdint>
 
@@ -41,7 +45,9 @@ int main()
         // at the throw site. boost::diagnostic_information extracts all of it.
         std::cerr << boost::diagnostic_information(e) << std::endl;
 
+        // tag::exclude[]
         #if (defined(__x86_64__) || defined(_M_X64)) && !defined(__MINGW32__) && !defined(__CYGWIN__)
+        // end::exclude[]
         // On x86_64, boost::stacktrace can capture the throw-site stacktrace
         // from the current exception via from_current_exception().
         // This requires linking with boost_stacktrace_from_exception.
@@ -50,7 +56,9 @@ int main()
         {
             std::cerr << "Stacktrace:\n" << st << std::endl;
         }
+        // tag::exclude[]
         #endif
+        // end::exclude[]
     }
 
     return 0;

examples/fmt_format.cpp

@@ -2,10 +2,12 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
+// tag::exclude[]
 #define FMT_HEADER_ONLY
 
 #if __has_include(<fmt/format.h>)
 
+// end::exclude[]
 #include <boost/safe_numbers/unsigned_integers.hpp>
 #include <boost/safe_numbers/bounded_integers.hpp>
 #include <boost/safe_numbers/fmt_format.hpp>
@@ -62,6 +64,7 @@ int main()
 
     return 0;
 }
+// tag::exclude[]
 
 #else
 
@@ -73,3 +76,4 @@ int main()
 }
 
 #endif
+// end::exclude[]

examples/safety_profile.cpp

@@ -27,11 +27,13 @@
 #include <iostream>
 #include <cstdint>
 #include <limits>
+// tag::exclude[]
 
 #ifdef _MSC_VER
 #  pragma warning(push)
 #  pragma warning(disable: 4127) // Conditional expression is constant
 #endif
+// end::exclude[]
 
 #ifdef BOOST_SAFE_NUMBERS_INTEGER_SAFETY_PROFILE
 using u32 = boost::safe_numbers::u32;